Heart attacks and strokes account for 3.4 million deaths annually in the United States. Moreover, the morbidity from vascular disease accounts for billions of healthcare dollars as well. The basis for these vascular diseases generally involves the formation of occlusive clots in the vasculature, leading to loss of blood supply, anoxia and tissue death. Current treatments involve the use of procedures that 1) promote fibrinolysis (tissue plasminogen activator), 2) prevent blood coagulation (heparin), 3) retard platelet-induced clotting (aspirin, ticlopidine) or 4) require surgical intervention (angioplasty, bypass, transendarterectomy). These therapies are either invasive or involve significant adverse effects. We recently have developed a targeted microbubble that binds to intravascular clots with high avidity. Preliminary work suggests that these microbubbles in conjunction with ultrasound can aid in the dissolution of vascular clots, It is the objective of this proposal to determine the feasibility and practicality of using targeted microbubbles along with ultrasound as a potential therapeutic modality in the treatment of vascular occlusion.